Soil Acidity and Manganese Nutrition of Corn and Soybeans as Affected by Lime and Nitrogen Applications in an Oxisol under a No-Till System
Caires, E. F., F. J. Garbuio, H. A. W. Joris and P. R. da S. F. Pereira . 2009. Proceedings of the International Plant Nutrition Colloquium XVI
Abstract
A 3-year field trial examined in a long-term no-till system the effects of surface-applied lime and N application on soil chemical attributes, grain yield and Mn contents in the leaf and grain of corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] on a loamy, kaolinitic, thermic Typic Hapludox in Parana State, Brazil. The treatments consisted of dolomitic lime broadcast on the soil surface at 0, 4, 8, and 12 t/ha, in the main plots, and N application at 0, 60, 120, and 180 kg/ha, in the subplots. Nitrogen was applied as N-NH4NO3 in top dressing on the black oat (Avena strigosa Schreb) crop during the autumn-winter seasons before growing corn or soybean during the spring-summer seasons. Surface liming increased soil pH and the content of exchangeable Ca, and decreased the exchangeable Al level at topsoil. Acidification in the topsoil was caused by N-NH4NO3 application. Higher acidification was observed with N application in the no-lime plots. Grain yields of corn and soybean were not influenced by liming. Application of N-NH4NO3 on the black oat crop has low residual effect on grain yields of corn and soybean. Liming decreased Mn content in corn leaf and soybean leaf and grain. Nitrogen application increased Mn content in corn and soybean leaf and grain. Surface lime and N-NH4NO3 applications at higher rates did not cause Mn deficiency or toxicity in the no-till corn and soybean crops with a sufficient level of Mn (DTPA-TEA) in the topsoil.
Key Words
Soil pH, Dolomitic lime, Nitrogen fertilizer, Leaf manganese, Grain manganese
